On 20 December, Sergo Borisovich Gerasimov, chief researcher at the Laboratory of Theoretical Physics JINR, Doctor of Physics and Mathematics, an outstanding Russian theoretical physicist, turned 85.

After successfully graduating from the Faculty of Physics at MSU in 1960, Sergo Borisovich entered the postgraduate course at LPI RAS, where his first mentors were Academicians M. A. Markov and A. M. Baldin. During these years, a unique style of scientific art and the topic of scientific works of Sergo Borisovich were forming. Since 1963, Sergo Borisovich Gerasimov has firmly connected his life with BLTP and JINR.

S. B. Gerasimov has a number of first-class results in the theory of electromagnetic and strong interactions of elementary particles. Achieved by S. B. Gerasimov sum rules for nucleon magnetic moments and spin-dependent cross-sections of nucleon and photon interaction, known as the Gerasimov-Drell-Hearn sum rules. These fundamental relationships, included in books on elementary particle physics, are discussed at special conferences. Their experimental verification is a priority task for modern accelerators.

Scientific interests of Sergo Borisovich are always connected with actual problems in physics of strong interactions. His recent works are devoted to important problems of the search for exotic mesons and narrow dibaryon resonances. He is distinguished by a close contact with experimentalists from JINR and other scientific centres.

S. B. Gerasimov is a laureate of the State Prize in 1977. His works were awarded with the 2 first JINR prizes.

Sergo Borisovich is a recognised expert in the most difficult questions of the modern particle physics. For many years he has been a member of the Dissertation and Science and Technology Councils of JINR and BLTP.

The breadth of scientific interests, great erudition, openness in communication, brightness, and constant goodwill of Sergo Borisovich arouse well-deserved respect and sincere sympathy among colleagues.

The JINR Directorate, friends, colleagues, students heartily congratulate Sergo Borisovich on his anniversary and wish him new creative success, prosperity, health, and happiness!